46 CFR 115.610 - Scope of drydock and internal structural examinations.
(a) A drydock examination conducted in compliance with § 115.600 of this part must be conducted while the vessel is hauled out of the water or placed in a drydock or slipway. During the examination all accessible parts of the vessel's underwater body and all through hull fittings, including the hull plating, appendages, propellers, shafts, bearings, rudders, sea chests, sea valves, and sea strainers shall be made available for examination. Sea chests, sea valves, and sea strainers must be opened for examination. The accuracy of draft or loading marks, if required by § 122.602 of this subpart, must be verified if not already verified at construction or a previous drydock examination.
(b) An internal structural examination conducted in compliance with § 115.600 of this part may be conducted while the vessel is afloat or out of the water and consists of a complete examination of the vessel's main strength members, including the major internal framing, the hull plating, voids, and ballast, cargo, and fuel oil tanks. Where the internal framing or plating of the vessel is concealed, sections of the lining, ceiling or insulation may be removed or the parts otherwise probed or exposed so that the inspector may be satisfied as to the condition of the hull structure. Fuel oil tanks need not be cleaned out and internally examined if the marine inspector is able to determine by external examination that the general condition of the tanks is satisfactory.